Well...... Sadly, I believe there isn't a card that is anti-xyz that will prevent them from summoning nor was a anti-synchro card that does the same. You can still build a deck without xyz.
For Example:
Quasar
Dragunity
Blackwing (mainly vayu turbo sometimes)
Heroes (only HERO gate)
Yillion wrote: :O Depends on what deck.
Just like what this person had said. You need to decide s theme for your deck.
Oh another thing, welcome to DA. Hope you enjoy your stay and always remember this guy cuz I am a proud Hero Duelist. Need any help for a deck build, just post it up at the Deck Building section and me or some other person will help you when they got the time.